00:00
This is a Triple J Podcast.
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You're listening to The Science Hour with Dr. Carl and me, Tanya Bunter. Once a week, we get to throw our questions at Dr. Carl and he answers them by using his big brain that is fascinated with the world around us.
00:14
On this episode, we delve into what is going on when we're daydreaming? Why, when we're really tired, do we get those vivid visions in our head? We also look at what screen time an AI is doing to us as we age and what makes the colours of the sunset. It's time to lock in and learn.
00:35
How are you feeling, Dr Karl?
00:38
Very good because I've got the opportunity to apologise for two mistakes I made last week.
00:42
I love when someone's like, I've stuffed up, let's let you know the truth. So what is it?
00:47
The first one was with regard to the food recommendations on reheating. And I said, oh, you can get away with it more than once and you can get away with it. Okay, here's the hard facts.
00:59
8% of the world's population gets food poisoning every year and half a million die. So half a million out of 8 billion is small. So this is a case of an event that is uncommon but catastrophic. And I'm just going to stick with the official food standards, Australia, New Zealand recommendations. I was kind of saying, I can probably get away with it. No, you reheated the food quickly and thoroughly and the centre has to be more than 75 degrees C.
01:27
You can buy a little food thermometer. I've got one for heating up the milk for making cappuccino and one for doing meat right there, about $10 each. And then if you do want to reheat out of the same block of food in the fridge, break it up first and leave some in the fridge and take it out. That was my first mistake. So official recommendations, heat up only one. Second one was about what happens to you when you go unconscious at the bottom of a pool, world record, and people dying by getting in water and then holding their breath underwater and the world record is 29 minutes?
02:02
And Mark Avery set me straight on that one. And I was saying, correctly, that the... The reason you breathe is not because you're low in oxygen, but rather the physiological center that runs in your body is that you're high in carbon dioxide. And if you're at the bottom of the pool having a competition with the other kids, do not do this at Christmas time, and you're just doing nothing, while your oxygen levels are dropping slowly...
02:31
your carbon dioxide levels are also rising but very slowly and that doesn't necessarily activate the mechanism. So you can then go unconscious. That's the pathway because the carbon dioxide levels are rising very slowly. Do not try to hold your breath under a pool as a game at Christmas time. Okay, I've got that off my chest. Please accept my apology for making that mistake and I'm so glad to have the opportunity to fix it up.
02:55
Thank you, Dr. Carl, for being so honest as well. I feel like both of those are very safe and important messages we needed to get across. Let's jump into some questions to kick off the science hour. Hello, Dr. Katie. What's your question for Dr. Carl?
03:09
Hi, doctors.
03:11
You know when you're daydreaming but your eyes are open and you can see everything around you but you can also see the thing in your head?
03:22
Like how does that work?
03:23
Ah. So what happens is that with normal vision, light comes in through the front of your eyeball and lands on cells in the retina. The light then causes electricity to happen, a chemical reaction happens, and then there's a lot of processing and 0.3 of a second later, you get this full 3D colour image of the world manufactured not by your eyeballs but by your visual cortices at the back of your head. Now, when you're daydreaming while awake, that is still running.
03:57
But on top of that, while your brain is still supplying you with continuous information, there's a cup of tea, there's a cup of coffee, there's people walking down the road, your brain's visual imagination systems have been switched off.
04:10
being switched on and then suddenly you'll realise that you're remembering time when you went for a pool or you were trying on some jeans in the shop and you found just the perfect ones and you've got these two streams existing at the same time. It's like you've got a screen at home and you've got two data projectors sending information, you've got two projectors coming into your reality and one can sit on top of the other. So your brain doesn't do it on top of your retina, it's happening at the back of your head.
04:39
How does that answer your question, Dr. Katie? I mean, it makes sense. It's pretty wild.
04:44
Yeah. But it is weird that whole, you always live three-tenths of a second behind reality. And so when you're thinking about people who are playing a sport like the AFL last week or cricket, and when the ball comes towards them, they do not have 0.3 of a second to react. So either... They've got a super fast pathway or they're reading the situation to work out which way the ball will be thrown or kicked or bowled at them. But certainly that's well within the 0.3 of a second normal reaction time.
05:18
It makes it even more special putting it in that sporting context. And I've got to say, daydreaming, what is the point of that? Because I personally daydream a lot. A lot of psychological reasoning must be there for us to still have that.
05:29
Ah, what sort of images do you get?
05:31
Um, look, it's a lot of fantasy stuff where I'm just hoping or wishing for something. So I sort of play out the situation in my mind.
05:40
Wow, you are so lucky to be able to do that. And then you can control it and then do something with it. Mind you, it's very important not to miss out on the fact that your house is on fire or something like that.
05:51
Okay. Well, we've got somebody else on the line to ask us a science question. They sent through a message on 0439 757 555. Dr. Alex, what's your question for Dr. Carl?
06:04
Hi, doctors.
06:06
A few weeks ago, I got an avulsion fracture in my ankle from playing tips at school. And I was wondering why the bones break and what is the easiest bone to break?
06:18
Oh, the easiest bone to break is your collarbone.
06:21
You know the collarbone there, Dr. Alex, in your neck?
06:25
Yeah.
06:26
Okay, now just start at your shoulder and feel your way along the collarbone and then gradually work your way to where it joins onto your sternum at the centre. And can you see a bit where it sort of changes curve from curving outwards to curving inwards?
06:43
Yeah. Yeah.
06:43
That's the point. That is where it breaks. It is the most commonly broken bone in the body and it's because your entire arm on the right hand or left hand side has only one single point of contact with your skeleton and that's on your sternum in the middle. Your whole arm, all the fingers, the forearm, the upper arm, the shoulder, the shoulder blade, they're all floating. And all the stress comes through that bone there. So that's the most commonly broken bone. And a bone is not just a lump of wood or calcium or steel.
07:16
It's a living composite. It's got a whole bunch of components like collagen to give it some flexibility and resistance to cracking. And then there's crystals. mainly a weird chemical called hydroxyapatite. It sounds like appetite when you're hungry, but it's spelled differently, A-P-A-T-I-T-E, and that makes it hard and gives it compressive strength. And then there are cells, living cells and blood vessels, and your bones are continuously being destroyed and rebuilt. And the way I remember it is that the osteoblasts blast has got to be in it they rebuild the bone and therefore the other ones they destroy it and so you're getting continuous repair all the time now imagine now i want you to make a have a mental image of a just a little wooden stick you got that middle image of a little wooden stick yep Okay?
08:06
Firstly, you can break it just simply by bending it, just snapping it over your knee.
08:10
Secondly, if it's a fairly skinny stick and you've got strong hands, you can twist it. And that gives you the spiral fracture. Thirdly, if you're really strong, you can push the stick from each end and make it crumple. I don't think people can do that, but that sometimes happens if you jump off a bit of a building, a bit of a height, and the stress goes straight up along the length of your leg bone. That's compression. And then... Repeated loading. So you can keep on loading your bone close to the breaking point, over and over and over, like bending, and then finally it does break.
08:43
And then finally something pulling on your stick. That's your avulsion fracture. So which bone was it?
08:50
The ankle.
08:51
Oh, you've got a bunch of bones there. Are things healing well?
08:56
Yeah.
08:57
And you've got a moon boot and all that sort of stuff?
09:00
Yeah.
09:01
Okay, look, follow the recommendations and do all the physio. And amazingly, in a couple of years time, it'll be like, I think I broke a bone with my left foot or my right foot. And you'll have healed because your body heals itself.
09:12
Well, how cool is that? The fact that we've got little crystals working to rebuild those broken bones. Thanks for your question, Alex. We also have Tim on the text line. He has a question about hair. Hello, Tim. What's your question for Dr. Carl?
09:27
Good morning, doctors. How are we? Good, mate.
09:29
Thank you.
09:31
It's a bit of a two-part question from my 10-year-old son. So I'm going a little bit bald, receding hairline and that, but at the same time, my beard's growing more, but it is black hair, a bit of grey, and it's also now getting ginger in it.
09:50
Yeah, what's the story there, Dr. Carl? Why would the colours be changing over time?
09:54
Okay, so with regard to hair growth and going bald, what happens is that the male pattern baldness on the skull is because the follicles, so you've got 100,000 follicles on your scalp and each of them is a little factory that makes one single hair shaft. 100,000 for dark hair, 80,000 for blonde people. And the follicles on the front and the top are sensitive to a chemical called dihydrotestosterone.
10:26
Now, you've heard of the chemical called testosterone?
10:29
Yep, yep.
10:30
Mate, there's a bunch of them.
10:32
It's not just one. And there's a bunch of receptors for them. And so you'll find that as you get older, you make different types of testosterone. Remember, evolution isn't perfect. It's good enough. If you're still alive after you're 21, hooray, good luck, right? And so they're genetically sensitive and what will happen on your scalp is is that the follicles themselves, the little factories, each factory gets smaller and smaller. So over time you get thick hair going to thinner hair and then very fine and then bugger all. Now the scalp is different from the beard.
11:06
In your scalp they're pretty well all the same and they all make the same hair colour but in your beard you can have one follicle manufacturing a reddish hair and another one right next to it managing a dark one and we don't know why. And also they've got different sensitivities. And so we're beginning to understand why people can have black hair on the scalp but a reddish beard and why the beard keeps on growing. And then the excuse that I used with my daughter when she was three years old and she believed this for a while was that the reason that I was getting a bit bald on top and instead growing hair on my nostrils and ears was because there were previously undiscovered anatomical channels running from the top of my scalp to my nose and ears and the hair was migrating down them.
11:51
And she believed that until she was about eight years old.
11:53
Oh, gorgeous. I lied to her.
11:57
Dr. Carl, every week you love to explore some things that you've learnt and you put it in a little newsletter. I was very interested about something you wrote about sweat. Can you tell us a bit more about the sweat you were writing about?
12:09
Okay, so you've got sweat glands all over your body and blood is 45% cells and 55% salt water. So you've got the sweat gland, we'll just pick on one, and blood flows past it on the inside of your body and a bit of the water comes out. and then comes out through your sweat gland onto your skin, and the blood flows on minus a tiny amount of water. Then, what sort of sweat gland did it go into? There's two. The one that's the most common is what's called the eccrine, E-double-C-R-I-E-N-E, sweat gland, and that gives a clear and watery sort of liquid, and basically, it's there to lower your core temperature.
12:51
You know, it's hot, you're doing exercise. But then there's another sort called the apocrine sweat gland and that's oily and protein rich, armpits and other parts of your body and it releases during different chemicals when you're sick or stressed or anxious or when internally adrenaline rises or cortisol rises. And the sweat from the apokine glands is odorless at first, but then the bacteria come and eat them and make them bad. And if you look into the actual sweat, you can pick up conditions such as changes in your sleep patterns like obstructive sleep apnea.
13:28
because you have a pause in breathing during the night and this can lead to high blood pressure but also you get an adrenaline spike and then you get the sweating and then you get different chemicals and then sweat and sorry stress and anxiety and we're heading towards something like the watch technology where you wear this bit of tech on your body like a wristwatch and it will have some sort of microfluidic sensors that'll say oh you might have such and such a disease so we're heading down that pathway and finally Night sweats, if you're having night sweats for more than two weeks, just go and see your GP.
14:03
You're probably okay, but more than two weeks, time to consult a doctor.
14:08
What are the links to having night sweats?
14:11
You can have situations such as tuberculosis or AIDS or a whole bunch of hidden diseases and obstructive sleep apnea and the whole body is interlinked. We're beginning to learn more and more. I don't know that much about it because I was trained as a doctor and a doctor is basically just a car mechanic. like a body mechanic, and you learn just enough. So physiology and histology and anatomy and biochemistry, they're all five, six-year studies, and you do a couple of months of each just to learn enough to recognize what might be wrong and fix up the patient.
14:44
You haven't done the whole six-year course of each of those because that takes several hundred years.
14:48
Well, it's very interesting and nice to confirm that apocrine sweat is something you can smell. My friend Indigo and I have discussed this. We can smell it very strongly on other people. So I'd love to read a little bit more about that. But we've got questions from other people that we'd love to get through. Hello, Joey, just six years old from Melbourne, getting in touch. What question do you have for Dr. Carl, Dr. Joey?
15:12
Hey, doctors. If people can live to 120 now, can I live to 150 now?
15:24
Almost certainly, Dr. Joey, you will be in the first generation to live forever. And by forever, I mean 500 to 5,000 years. And I will be in the last generation to die and Tanya might be somewhere in between. Oh.
15:42
So it turns out that you've got all these cells in your body and they've got programs in them to age and get older. And every now and then they do their thing and you get older. And occasionally we've come across creatures that are able to reverse that. So we're heading down that pathway with genetics. And so this program to cause programmed cell death, we call that apoptosis. weird word, A-P-O-P-T-O-S-I-S, which literally in Greek means the yellowed leaves in autumn falling down from the trees all dead.
16:19
And we can find that program and fix it in your life. So just to give you some positivity, you ready for some positive stuff, Dr. Joey?
16:29
Yep.
16:30
Okay. Right. There's a bit of a poly crisis going on. So here's number one. You are living in the most peaceful generation ever in the history of the human race. Get your parents to read the book, The Better Angels of Our Nature by Steven Pinker.
16:45
And the reason you think things are so bad is because of the motto of the commercial media, if it bleeds, it leads. Secondly, you are smarter than your parents and me. This is called The Flynn Effect. Okay. and the IQ is going up by the rate of nine IQ points every generation.
17:01
And thirdly, we can stop and reverse global warming by simply keeping fossil carbon in the ground. So be positive and look forward to enjoying your incredibly long life and occasionally think of me.
17:12
Oh, Dr. Joey, that's so exciting to have all these positive things, big brain, long life, and the most calm time in the world at the moment. Thank you so much for your question, Dr. Joey. 0439 757555 is the best way to get in touch with us. Let us know your name and your science question for Dr. Carl. With me on the line out of Melbourne, we have Dr. Graham.
17:37
G'day, doctors. My cat...
17:41
might be going on heat at the moment. And she had a pee in the cat litter last night and it stunk. It was really bad. So I threw some bicarbonate of soda on the cat litter And it dispelled the smell.
17:57
So how does that work?
18:00
There's a bunch of different ways. So the thing to realise is that the smell is related to the nitrogen and different creatures get rid of their nitrogen in different ways. If you're a fish living in the ocean, mate, you just squirt it out all the time. You know, there's all this water around you.
18:17
If you're a mammal or a creature that lives on land, you shove it into the urine along with other chemicals. But if you're a bird, you've got to minimize weight. So what they do is they just have a little paste, right? So what you're looking at is a way of getting urea, which has got nitrogen in it. And then as the bacteria break down the urea in the cat urine, they produce ammonia and that's one of those nasty smells. And so you're thinking, well, ammonia is alkaline and bicarb is alkaline, so how does alkaline remove alkaline?
18:54
It doesn't work that way. So firstly, bicarb has got this huge surface area, so it's a fine powder, so it just absorbs some of the stinky chemicals onto its surface. And then it can... buffer some of the acidity and alkalinity, keeping the chemical environment less favorable for some of the other reactions. And there are acids in there and it will react with the acids. So vinegar turns into sodium acetate. And then the ammonia, well, it doesn't really neutralize the ammonia. The ammonia is still there, but it gets rid of all the other chemicals.
19:28
So having bicarb and an absorbent litter and then removing it regularly will reduce the stinky thing. And is your cat an indoor, an outdoor cat?
19:38
Mostly indoors.
19:40
Right, because the thing with cats in Australia is that each day they kill a million birds or 12 every second. And so by keeping it indoor, you are doing good work for Australia.
19:52
Thank you so much for being so responsible, Dr Graham. 0439 757 555. Another question from Dr Zara. Dr Zara, welcome.
20:02
Hi, doctors.
20:04
My question is a bit spacey.
20:07
Okay, my question is, have you seen any radiation from planets or stars or have you seen any of them glowing?
20:15
We have. Basically, trying to see a planet far away next to a really bright star is like looking at a really bright headlight and somebody's got the most gutless little torch right next to it.
20:31
you know, and that's our problem. And so the scientists have come up with various ways. So we have actually, with various masking technologies, have been able to pick up the light from different stars and occasionally, so the sun, its star will shine light on that planet and by masking out the star we can just see the planet. We can also, as the planet comes in front of the sun, in front of the distant star, for a brief moment, its atmosphere is the only thing that crosses the front of the star.
21:05
Really? Because, so imagine you've got a planet like Earth, 12,000 kilometres across, 14,000 kilometres across, with an atmosphere, say, 20 kilometres thick. For a very brief time, to a distant observer, as we go across the front of our sun, the only bit that crosses is the atmosphere, and that might be for a 50th of a second, and then the rest of the planet follows. So we've been able to pick that up. So we can pick up visible light from stars, and just last week we picked up electromagnetic radiation, which we think is almost certainly an aurora.
21:41
So this distant planet has an atmosphere and the atmosphere has activity from the sun. And by the way, just to finish off, a colleague of mine, Matthew Bailey, when I was a TV weatherman, Matthew Bailey, an Australian astronomer, reported... making the first discovery of another planet around a star. And then, six months later, he said, I made a mistake. And when he made the mistake, he admitted this in person to a whole bunch of astronomers, and they all stood up and applauded him.
22:15
So in one side of our society, you'll have people say, oh, you changed your mind. You're backflipping, you weak bugger. Whereas in science, it is, I hold my theories on the tips of my fingers so the merest breadth of fact will blow them away. So I've got another advertisement in there for scientists.
22:32
Beautiful, beautiful way to look at your job. Thank you for your question, Dr. Zara.
22:39
It is the Science Hour with Dr. Carl and Dr. Tanya. So lovely to be able to lean into some of those weird questions we have.
22:46
0439 757 555 is the best way for you to get in touch with us. Our first question from Byron Bay, Dr. Remy. What's your question?
22:55
Hey, doctors. I was wondering what makes the colours of the sunset?
23:01
Raleigh's Law of Scattering, R-A-Y-L-E-I-G-H, and it's the other half of why the sky is blue.
23:11
So in our atmosphere, it's to do with scattering, and that's a special word that the scientists use in a way that's different from how you and I use it. For a physicist, scattering is when electromagnetic radiation, in this case light, lands on a particle, is absorbed and then emitted.
23:29
And in this case, the particles we're looking at are particles of gases, nitrogen molecules and oxygen molecules. They absorb the visible light and then they re-emit it. And here's the weird thing, they tend to re-emit it more at right angles and slightly bluish. And in the case of when you're looking at a sunset, you're looking through a lot of air. When you're looking straight up, vertically above you, you're looking through what they call an optical air mass of one.
24:01
So there's a certain number of air molecules between you and the end of the universe, and that's called one. But when you're looking directly across at the horizon, the sun is just kissing the horizon, The optical air mass is around 30 to 40, and so that effect where the blue gets bent away more is much more pronounced, and so you tend to see a red sort of hint. And then in the Bible, in Matthew something something, I forget the verse and chapter, some Pharisees come along to Jesus and say, hey, smart man, hey, tell us about how come it's red at night.
24:33
And he's trying to give moral lessons and stuff. He says, yeah, okay. And he actually does say that a red sky at night is indicative of fine weather tomorrow. And that's when the sun is below the horizon. It's maybe, you know, the sun is set maybe 10, 15 minutes away. And then it's still sending light to the air above you.
24:57
And that light is red, so the sky goes red. And the only way you can do that is if there's no clouds in the way. And in some parts of the world, the weather comes from the west, like in that part of the world on this side of the equator and Sydney, Perth on our side of the equator. And so if you're seeing a red sky and the weather's coming from the west and the sun is in the west, it means that there's no clouds. So you'll probably have a fine day tomorrow.
25:22
Beautiful. Remy, you're 15 years old, so you're at school. Have you been learning much about refraction and light and things like that yet?
25:30
Yeah, yeah.
25:32
No, not really, but hopefully we're learning more about that soon.
25:35
Yeah, something to bring up with your teacher. I feel like I was learning about that around this age. Dr. Carl?
25:40
Yeah, and Dr. Remy, I'm very happy to do a free science Q&A with your class. I do it every week, every Wednesday afternoon on a Wednesday afternoon, 1 till 2, 2 till 3 Sydney time. So go on to drcarl.com, D-R-K-A-R-L.com and make a booking. And I look forward to talking with you down the wire on the internet, not IRL or F2F.
26:01
That sounds like a pretty good idea. Thank you, Remy.
26:03
Thank you so much. I talked to my science teacher.
26:06
Love that. Thank you, Remy. You're listening to Dr. Carl and Dr. Tanya going through your science questions. We have another question up on the line. Dr. Tommy, what do you want to know?
26:18
Good morning, doctors. How are you? Good. Thank you, mate.
26:23
Look, I don't eat any animal products and I was just wondering whether I'm being lax or being a little bit silly when thinking that vegan food doesn't go off nearly as fast as animal products and also how long will vegetables last in the fridge if I'm keeping them cold and then reheating portions?
26:44
Ah, okay. So I would recommend going to No Money, No Time. That's the website.com. with Claire Collins, Professor Claire Collins. She's a friend of the show, our go-to person, University of Newcastle. And the bottom line is that if you have a meal of meat and three different veg, mate, you've got all your nutritional needs, dead easy.
27:09
If you go vegetarian, you have to know a little bit more about the food, but basically you can be fully healthy and if you're a woman, carry a baby and bring the baby up vegetarian. Vegan, you've really got to know what you're doing. Are you vegan, sorry, or vegetarian?
27:25
Yeah, I've been vegan for five years. Okay, and so you've got to really know what you're doing. And so, for example, when you're growing the baby as a woman, which you wouldn't do being male, but unless you follow that movie called Twins with Arnold Schwarzenegger and Danny DeVito, if you're growing a baby, you have to really change your diet. And then when the baby's born... You have to cut back on fibre and give it more fat. Anyway, so even if you're totally vegan, you can still get infections. So rice is the classic one where a bacterium in it called Bacillus coeruleus, as in blue, will grow and you can get infections.
28:03
Meat has the advantage for bacterial infections of being a natural culture broth. It's got fat proteins and carbohydrates. So bacteria love to grow in meat. They're less likely to grow in vegetable type products because they're lower in the protein, but they will grow there. So you've got a slight advantage. Is that kind of helping a little bit?
28:24
Yeah, it is. And I guess it's not a free pass. Just because I'm eating vegan food doesn't mean that it's not specifically going to be safer.
28:33
That's good to know. Yeah. I'm happy we're spreading some real knowledge around that because I feel like even just saying natural culture broth, I feel like we've got dr tommy winning being as a vegan person hearing that makes me feel a little bit unwell to be honest we've got another question from dr ivy who's just 10 years old hello dr ivy what would you like to know from dr carl um good morning doctors my question is why are mosquitoes attracted to the lights outside at night ah dr ivy this is another chance for me to apologize for a mistake i made in the past Say that's okay, Dr. Carl.
29:14
Okay, thank you.
29:15
Okay, so what I used to say which was wrong is that before humans had lots of lights around the place, mosquitoes travelling at night would navigate by the moon.
29:29
and they would keep the moon on, say, the right side, and then that way they could go in a straight line because the moon was so far away. I was wrong. And then I said with a huge increase in artificial lighting, then there's a light close near you, and if you try to keep a light on your right-hand side, Mate, you're going to do a circle around it. And I was wrong. I was wrong. It turns out that mosquitoes use the lights to navigate to keep the light away from their belly.
30:02
So if the moon is above you rather than on the horizon, the mosquito will just sort of fly along in a straight line and avoid putting the light on its belly. When the moon's on the horizon, which it doesn't spend much time, then the mosquitoes get a bit confused. So the mosquitoes then going around the light, they will then flip on their side so that while they're going around the light, the top of their body is facing the light and the belly is facing away and this puts a huge load on their aerodynamic flying and then they tend to die.
30:39
And does that help a little bit, Dr. Ivey, that they use the light as a navigation aid to make sure and they try to keep the light on their back, not on their belly, does that help?
30:51
Yes, that helps much more. Sorry, I was just going to say it really helps to imagine that as well. Sometimes you look at them and it feels so aimless and chaotic when they're flying around a little light. So it's nice to know the reasoning behind that. They're not actually settling in. Yes, Dr. Carl.
31:08
They're not chaotic, as you've pointed out. They've got this massive muscular overload trying to fly sideways rather than with their belly facing the ground. And have you been reading in the papers how in New South Wales there's been a bit of a bogone moth infestation?
31:24
I have actually seen this terrifying, a little bit gross, they eat your clothes, surely.
31:29
Well, they're part of a migration. They go from Queensland, just over the border, through New South Wales into Victoria. And this morning, we've got a front door, which has got a wooden front door and a bit of an air gap and then a screen door. And I opened the wooden door this morning to get the newspaper and five million trillion bogot moths came into the house. Okay, 20, maybe 10. Okay. Still a lot. Yeah, okay. It was just a surprise and somehow they'd snuck into that little tiny gap at the bottom of the screen door and they were just there on the wooden door and I opened the door and then suddenly I got a face full of moths and it's part of nature's great symphony of life.
32:07
The ebbs and flows of the moth laugh.
32:11
Are you ready to jump straight into some more questions? To the audience. Amazing. Dr Thomas from the Sunshine Coast, what do you want to know?
32:19
Hello, Carl. I'm just wondering, when I'm really tired and before I go to sleep, I have all these really stimulating thoughts and they can keep me up. They're so exciting. But when I'm not tired, I'm trying to sleep, my brain won't do that. And I feel like that's...
32:33
needed to go to sleep. What actually is that happening in my brain?
32:37
That's so interesting. I actually get the same thing all the time, especially when I used to do Middawns on Triple J, the vivid dreams that I would have, or like the way things would flip into different shapes. What is going on, Dr. Carl?
32:51
Yeah, I've been through that pathway, and on one occasion, I discovered the secret of the universe. Oh!
32:55
You've got an answer to stopping this from happening.
32:58
Almost. And so the next night I went to bed with a notepad and pen besides the bed and I said to myself as I was falling off, tonight I'm going to do it, write it down, write it down, write it down. And when I woke up in the morning on the sheet of paper, I had written down about 20 times, write it down, write it down, write it down. That's what I wrote 20 times while I was asleep.
33:19
Wow.
33:19
And I missed out writing down the secret of the universe.
33:21
It's so interesting. A lot of musicians talk about putting a little pen and pad next to you to get those weird creative thoughts out. For some people, it's a very stimulating time. What's going on in our brains? Why does that happen?
33:34
Well, when you're tired, you're moving from waking into that weird territory between wakefulness and sleep. And so you're losing what's called the executive control, or look it up in Wikipedia, it's called the default system, weird name. And that's your prefrontal cortex becomes less effective. The prefrontal cortex is what really big in us as compared to the primates and we use that for the things that make us human like poetry, income tax and weapons of mass destruction.
34:05
So your executive control weakens and then your thoughts start jumping around and suddenly you make connections between this and that. And so for a musician, they might suddenly create this riff that has never existed so far before. But also your attention becomes unstable and the bad side is you can't concentrate on one thing. But the good thing is you can link a whole lot of different things together. So you're jumping from this to that and...
34:30
then you lose your filter overall. Normally, a lot of thoughts are just thrown away before they make consciousness. And in this case, they don't. So you're getting all these ideas running through your brain. And that happens to me sometimes. And I've found the best thing is to shut my eyes and...
34:47
if I just shut my eyes and I look, I can see a very faint flickering of light, maybe here or there. It's not total blackness. And I've tried to follow that blackness, that little flickering light. And as I follow it around, something happens.
35:01
Well, it's very good to know that we can just put a little notepad and pen down to get that out of our system.
35:07
Dr. Tani, you've got a question for Dr. Carl. What is it?
35:11
Hi, doctors. Yes, I had a follow up question to like your big brain and aging answer and how screen time and AI is affecting that and like the shrinking brain theories.
35:25
So firstly, the brain does shrink, but that doesn't mean that it's less effective. It's part of normal aging. Remember, evolution is not perfect. It's good enough. And so, yes, a shrinking brain is not a shrinking mind. Secondly, the links between lots of smartphone use and then brain structural activity – very very wobbly these studies are not good yet they might become better sooner and then screen time isn't just one thing so you can spend an hour playing a complex strategy or reading a deep book on an iPad or learning a language or just going doom scrolling which I love doing so we don't know the relationship between screen time and the shrinking brain but certainly a shrinking brain is not a shrinking mind does that answer your question Tani?
36:13
a bit
36:14
Yeah.
36:14
No.
36:15
Yeah? Yeah. I feel like that makes sense. There's a lot of plasticity in the brain and even if it is getting smaller, it's able to use different parts in a more efficient way. Does that make sense, Tani? Yeah.
36:26
Yeah, yeah. I'd love to see more studies done on it.
36:29
Yeah, maybe it's one we come back to. Thank you so much.
36:33
0439 757 555. That's the way you can get your questions in to Dr. Carl for the Science Hour. We have a very interesting one. I don't know much about this, Dr. Carl. It's all about decagons. Have you heard of that before?
36:46
Yeah. Dr. Aaron has a question about decagons.
36:49
It was just in the paper.
36:51
Yeah, tell us more. What's your question, Aaron?
36:53
Good morning, doctors. Yes, I've just seen that as well. So my fascination, I'm an amateur astronomer, major enthusiast.
37:03
The question being, there's a decagon on Saturn because our polar axis is just facing us at the moment. We've been able to photograph it.
37:13
Is it true and how does that form on a gas giant?
37:18
We don't know how it forms. The study of weather is called meteorology from the ancient Greek word meteor, meaning atmosphere.
37:28
And so those little rocks you find flying through the sky, they happen in the atmosphere, they call them meteors. We've known that there has been a stable hexagon, a six-sided hexagon at Saturn's North Pole, and it's been there since the 1980s, and it's stable. But now we've found in the southern hemisphere, just recently, this short-term stable ten-sided, or decagon, and we can come up with some sort of mathematics to tell us how it got there, but we don't know enough about the atmosphere of Saturn to tell whether it's going to keep on staying there for a long time.
38:04
Will it stay there for four decades? No, we don't know. It just appeared recently, and it might be driven by jet stream instabilities. We've got no idea. So on planet Earth... We've got this weird thing where there's been global warming caused by the fossil fuel companies and then that has caused extra heat in the system. It's changing the pattern of winds that go around the North Pole and instead of going around and being strong, they sometimes weaken and suddenly bursts of really cold air come down from the North Pole into, say, the top bits of the USA.
38:38
So what's going on with this guy?
38:41
Keep watching. We'll find out.
38:43
Yeah. Well, thank you so much for putting me onto something new to learn, Dr. Aaron. That is the end of Dr. Carl answering your science questions for today. Thank you so much for hanging out with us. My name's Tanya Bunter. This is So You Know, if you've just tuned in and you're like, damn it, I've missed all of the questions. A great way to jump back in is by going to the Triple J app. And hey, Dave Woodhead is going to be coming up for you very soon as well. So make sure you stick around for all of that. And just a reminder, Dr. Carl happens each and every week here on Triple J.
39:17
This is a place where you can ask your questions. 0439 757 555. I am constantly looking at what you are sending through and saving them for Dr. Carl to tick off on. So get those questions in 0439 757 555. Thank you so much, Dr. Carl. We'll catch you next week.
39:36
Dr. Carl, sharing a wealth of knowledge with you again for another week here on Triple J. Massive props to our producer Ella and the Triple J Ops team who make sure this show gets into your ears. I'm Tanya. I can't wait to do it with you all again. Catch you next week.
39:52
Dave Marchese here from the Triple J Hack team. Hey, if you love Dr. Carl's podcast like I do, you might enjoy the Hack podcast as well. Each day we bring you the news that matters to you, from the latest science on climate change to what's happening in politics and news around the world. The Hack podcast. It's your daily fix of the news you need to know. Get it wherever you're listening now.
